Broken Yamaha F150 - Need Help

[kjfleming]

I'm new to the iBoats forum. I am a forum member at WalleyeCentral.com and the site administrator over there suggested I post the problem I am having with my Yamaha F150 over here as well. Thanks for reading (it's long) and thanks for any suggestions/help you are able to give. This is cut-n-pasted from the other forum:

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This will be a little long, I apologize in advnce. I have a 2005 Yamaha F150 hanging on the back of a 2005 1850 Reata. Started having problems with the F150 back during the first weekend of August. Through 2-solid months of boating I've been getting about 43-44mph @ 5700rpms running a 15-pitch Revolution-4 prop (I boat at high altitudes). Up to this point, F150 has run flawlessly this year. During the August weekend trip, after one full day of boating, I noticed that the engine was losing power. By the second day, it got to the point where the F150 struggled to get the boat on plane. I'd give it full-throttle and the rpms would spin up to about 5000rpms, then w/o backing off the throttle the rpms would fall on their own as the motor lost power. I was now getting about 3700rpms @ WOT. The odd thing is there were no other signs of something wrong: F150 started fine, sputtered a little when put in gear, but it idled fine with no abnormal shaking or grumbling. I've been using the same prop/hub-kit all summer.

I did some research on the forum and read about other Yamaha owners' problems with clogged VST-filters and fuel injectors. I printed off a couple of posts and took the boat into a mechanic. They checked the fuel lines, anti-siphon valve and the fuel filters and couldn't find anything wrong. Their Yamaha mechanic was out of town and they didn't feel comfortable going any futher. They told me to lake test it one more time and if I still had problems to take the boat to a certified Yamaha mechanic.

The F150/boat is now at the second mechanics for a second time. During the first time in they:
* ran motor on the Yamaha computer = no codes showed up
* checked fuel pressure = good
* checked the VST screen/tank = good
* installed Yamaha 10-micron filter
* fired each injector individually = injectors fired ok
* checked both fuel pumps = good
* mechanic felt that fuel pressure was good up to the injectors
So, they called me and told me they couldn't find anything wrong. They added some SeaFoam to the gas tank and told me to come pick it up and lake test it. Put it on the water, same problem: very low engine power (I thought I was going to have to use the Minnkota to get back to the dock). They had me check the primer bulb on the lake while underway...2 squeezes to firm.

I did buy the boat used last Spring with a clean bill of health from the dealer. A few weeks ago I even contacted the first owner and he said that he'd never had any problems with the F150. Needless to say, the mechanic was not very happy to see me today when I dropped the boat off. He told me he's really stymied with this one. I asked him if there's anyway to check the fuel pressure on the spray side of the injectors beyond just checking if they fire. He said, yes, but it would be time and money.

OK, thanks for reading this far. Any thoughts? I'm by no means a Yamaha/motor expert (have owned two small 2-stroke Johnsons previously). The mechanic seems open to ideas and suggestions.

Thanks for any help you're able to give. I'm hoping I can get it fixed before it's time to winterize and store.

 

[JRJ]

Re: Broken Yamaha F150 - Need Help

Welcome to iboats. Until an expert shows up, I suggest doing a search on F150's. Chances are your problem has been covered. Good luck.

 

[tommays]

Re: Broken Yamaha F150 - Need Help

look for a dealer with a Yahama MASTER TECH

yamaha-motor.com/outboard/training/toptechnician.aspx

Tommays

 

[JB]

Re: Broken Yamaha F150 - Need Help

This is from left field, Mr. Fleming, but have any of these guys tested the boat for excess weight (water) or drag?

Also, have they put your engine on a dynamometer? That will tell them in one shot if there is anything wrong and how bad it is.

Changing/cleaning stuff in the hope that the problem will automatically go away is pretty amateurish troubleshooting in my view.

Hope that gives you an idea or two.

Good luck, and welcome to iboats.

 

[rodbolt]

Re: Broken Yamaha F150 - Need Help

first have a leakdown test done. takes 15 minutes tops. this will confirm mechanical integrity. then run a spark test, 5 minutes tops.
then if fuel rail pressure is within specs I would send the injectors to a service facility for testing.
I use Flagship marine and UPS delivers.
with no codes set it greatly reduces trouble shooting time by eliminating a whole rack of issues.
time to look at stuff the ECU does not monitor.

 

[kjfleming]

Re: Broken Yamaha F150 - Need Help

rodbolt, thanks for the insight. Do you have a telephone number for Flagship Marine that I can pass along to the mechanic?

-kjfleming

 

[rodbolt]

Re: Broken Yamaha F150 - Need Help

google flagship marine in Florida or have your tech look in either the 05 or 06 marine tech guide for the address and phone numbers.
the place is recomended by yamaha and its in a tech bulliten.

 

[kjfleming]

Re: Broken Yamaha F150 - Need Help

Like I mentioned at the top, the administrator at the WalleyeCentral.com forums recommended I post over here. He also said that if I got a response from "rodbolt" to feel incredible fortunate and take the advice as law. So, rodbolt, thanks again for your help. I called my mechanic this morning and carefully shared your input. He seemed very hesitant over the phone. He muttered something about essentially testing the fuel-rail pressure last time the boat was in and that because it was good, this time he was looking outside the fuel system. He disagreed with running a leakdown test on a motor that was so new, and then mumbled about not feeling it necessary to ship fuel injectors across the country to get fixed. He said his next step was to call Yamaha and get some advice.

So, my question is, will Yamaha be helpful when he calls OR should I go pick up my boat and try the other Yamaha mechanic in town. My problem is that there are really only 2 Yamaha mechanics in Denver (unfortunately no Master or even Certified mechanics in town) that have been servicing Yamaha's for more than a few years. I really do not want to burn a bridge with one of them unless I have to.

 

[JB]

Re: Broken Yamaha F150 - Need Help

Your advisor was correct, Fleming. You can take rodbolt's advice to the bank.

I still think a dyno run is necessary. Any shift in the shape of the torque curve could point to the problem.

 

[zzzzz]

Re: Broken Yamaha F150 - Need Help

Flagship is right down the street from us here in town...(941)639-3738...been dealing with them for years

 

[rodbolt]

Re: Broken Yamaha F150 - Need Help

NEVER take my word.
first law.
however if the rail pressure is good and the ign system is working the only way to actually verify fuel flow into the cylinder is to flow test the injectors.
no other way on that engine.
leak down test will take less thn 15 min on that motor and should be done.
your tech is an idiot and if he calls Yamaha the RTA is gonna tell him that .
in the tech guide is a systematic list of troubleshooting procedures.
if the tech follows it to the letter by the time he/she is done the problem is idetified.
a caveman can do it.
have your tech post to me. I dont mind explaing how it works.
and yes I have seen "new" engines fail. its rare but lean running can do it.
but from your description your tech leaves a lot to be desired.ask him flat out and straight up if he has a leakdown tester and knows how to use it.
if either answer is no then go find a real shop.
I hate to sound nasty or snippy but to many techs and shops are simply ripoff joints.
I did a TBI volvo yesterday that went through 4 shops in 2 weeks,lots of parts had been installed.
the problem was a defective low oil pressure switch. took 4 minutes to find it.

 

[kjfleming]

Re: Broken Yamaha F150 - UPDATE (FIXED!)

Re: Broken Yamaha F150 - UPDATE (FIXED!)

A Quick Update: mechanic finally pulled and cleaned the fuel rail and all injectors last week (said he had to unclog #4 injector) and lake tested it. I picked up the boat on Saturday and put it on the lake yesterday. Motor runs better than when I bought it (used) in the Spring. Before all of this debacle I was getting about 43mph @ 5800rpms at WOT fully trimmed out. Yesterday (after repair saga) I was getting 45mph @ 6000rpms and I wasn't even fully trimmed out, which is great at our high altitude. Motor would have gone above 6000rpms had I trimmed the last little bit. Best part, the mechanic didn't charge me for this most recent time in. So, after about 2-months, 2-mechanics and many trips back-n-forth, my F150 is finally running great again. Had a Yamaha 10-micron fuel filter installed. ONE QUESTION: what's better to run on a regular basis, fuel conditioner (Sta-Bil or Sea Foam) or Yamaha Ring Free (maintanence level) OR can I run both simultaneously during regular summer-season fill-ups.

Again, many many thanks for the great advice (especially rodbolt). I'm grateful.

-kjfleming